1. Field of the Invention:
This invention relates to improvements in ophthalmology and more particularly to supporting systems for artificial intraocular lenses (pseudophakoi) used for correction of aphakia and re-establishment of binocularity in aphakia.
2. Discussion of the Prior Art:
Well-fixed and well-centered intraocular lens implants are known to produce stable retinal images and offer the best chance of re-establishment of binocularity in cases of aphakia.
A characteristic common to presently employed lenses which thwarts the normal activity of the aphakic eye's pupil, however, is the maintenance of a constant minimal pupil size as determined by the radial spacing of posterior projections of non-yielding post-irido loops or clips. A pilocarpine regimen is usually necessary to avoid accidental lens dislocation occurring as a result of pupil dilation.
Supporting systems which can accommodate for normal dilation and contraction of a dynamic pupil have been made the subject of a copending application for patent bearing Ser. No. 587,483 and filing date of June 16, 1975 now U.S. Pat. No. 3,975,779.
These latter systems, having been designed to apply a constant holding force against the pupil margin under maximum normal dilation and beyond (i.e. medically induced abnormal dilation) for purposes of avoiding axial displacement of the pseudophakos, have a disadvantage of tending, in some applications of use, to traumatize the pupil margin and/or produce excessive distortion of the normally circular pupil configuration. These problems, when existent, occur to their greatest extent during pupil contraction, e.g. in response to bright light or artificially induced situations.
Accordingly, an object of the present invention is to overcome the aforesaid and corollary drawbacks of intraocular lens-supporting systems which can accommodate to normal dynamic pupil function and to accomplish this without danger of displacement of the pseudophakos after proper implantation.
It is also an object of the invention to render possible the placement of pseudophakoi in either the anterior chamber of an aphakic eye or the more natural lens position posteriorly of the iris diaphragm; and
A more general object is to provide for improvement in structure, function and applicability to the aphakic eye of pseudophakoi which can accommodate to dilation and contraction of the dynamic pupil.
Other objects and advantages of the invention will become more readily apparent from the following summary of the invention and description of the preferred embodiments.